The Collaborative International Dictionary of English v.0.48:

Egotistic \E`go*tis"tic\, Egotistical \E`go*tis"tic*al\, a.
   Addicted to, or manifesting, egotism; having an exaggerated
   view of one's own importance or good qualities.

   Syn: egotistic; narcissistic; self-loving; conceited; vain;
        self-important; opinionated.
        [1913 Webster + WordNet 1.5]

WordNet (r) 3.0 (2006):

egotistical
    adj 1: characteristic of those having an inflated idea of their
           own importance [syn: egotistic, egotistical,
           narcissistic, self-loving]
    2: characteristic of false pride; having an exaggerated sense of
       self-importance; "a conceited fool"; "an attitude of self-
       conceited arrogance"; "an egotistical disregard of others";
       "so swollen by victory that he was unfit for normal duty";
       "growing ever more swollen-headed and arbitrary"; "vain about
       her clothes" [syn: conceited, egotistic, egotistical,
       self-conceited, swollen, swollen-headed, vain]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "egotistical":
   acquisitive, ambitious for self, autistic, boastful, boasting,
   bragging, careerist, conceited, crowing, egocentric, egocentristic,
   egoistic, egotistic, grasping, greedy, individualistic, narcissan,
   narcissine, narcissistic, narcistic, overweening, personalistic,
   possessive, privatistic, proud, remote, self-absorbed,
   self-admiring, self-advancing, self-besot, self-centered,
   self-considerative, self-contained, self-devoted, self-esteeming,
   self-indulgent, self-interested, self-jealous, self-occupied,
   self-pleasing, self-seeking, self-serving, self-sufficient,
   selfish, swelled-headed, vain, vainglorious, vaunting